Zinc (Zinc PCA / Zinc Oxide)
An essential mineral that regulates sebum, fights acne bacteria, and provides physical UV protection — the oil-control essential.
What Is Zinc (Zinc PCA / Zinc Oxide)?
Zinc is an essential trace mineral involved in over 300 enzymatic processes in the body, including DNA synthesis, cell division, and wound healing. In skincare, zinc appears in several forms: Zinc PCA (zinc pyrrolidone carboxylic acid) is the oil-regulating form used in serums and toners; zinc oxide is the mineral UV filter used in physical sunscreens; and zinc sulfate or gluconate appear in acne treatments. Zinc PCA works by inhibiting 5-alpha-reductase, the enzyme that converts testosterone to DHT (dihydrotestosterone) — the hormone responsible for stimulating sebum production. This makes it uniquely effective for controlling oil without drying the skin. Zinc also possesses antimicrobial properties against C. acnes and anti-inflammatory effects that calm active breakouts. The classic The Ordinary Niacinamide 10% + Zinc 1% formula popularized zinc PCA as an oil-control companion to niacinamide.
Key Benefits
- Regulates sebum production by inhibiting 5-alpha-reductase
- Antimicrobial against acne-causing bacteria (C. acnes)
- Reduces inflammation and calms active breakouts
- Zinc oxide provides physical UV protection without chemical filters
- Supports wound healing and skin repair
- Helps maintain skin's natural immune function
How to Use Zinc (Zinc PCA / Zinc Oxide)
For oil control and acne, apply a Zinc PCA serum (1–2%) after cleansing and before moisturizer, 1–2 times daily. Zinc PCA is lightweight and absorbs quickly. For acne spot treatment, apply a thin layer of zinc oxide paste to blemishes overnight. Zinc-based sunscreens (zinc oxide) should be applied as the last step in the morning routine. Zinc PCA is well-tolerated but very high concentrations can feel drying — start with once daily if you have combination skin. The niacinamide + zinc PCA combination is the most popular way to use zinc in K-beauty.
Pairs Well With
Classic pairing with niacinamide (The Ordinary made this famous). Also works well with salicylic acid (double oil control), hyaluronic acid (hydration buffer), and centella asiatica (soothing).
Avoid Combining With
Avoid combining with copper peptides in the same step — zinc and copper compete for absorption. Also avoid using zinc oxide sunscreen over chemical sunscreens (pilling). No other major conflicts.